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Connecting Electric Water Heaters

A water heater is a simple device. Cold water enters from one side of the tank, where it is heated by electricity, gas or propane, and hot water exists from the other side. In BC, it's common to install electric hot water heaters while gas is used in Alberta and propane in remote locations. Connecting electric water heaters to the electrical supply is governed by Canadian Electrical Code.

Electrical Connection

The installation is based on the CEC-2015 section 62-114. A GFCI breaker is not required but most manufacturers do request it as a part of their installation procedure.

We put electric storage-tank water heaters on their own circuit to avoid tripping the breaker with other loads. If a shared circuit were used, there could be constant overloading with other appliances that would trip the circuit breaker.

Not only is this inconvenient but tripping too many times will wear down the breaker contactors and eventually it will not trip at the designated value, leading to a very serious electric overload and overheat condition that could escalate to an electrical fire anywhere along the branch circuit.

Sharing a circuit may save time, effort and materials in the short run but can cause disastrous losses in the long run.

Connecting electric water heaters according to the Canadian Electrical Code.
Electric water heaters are common in BC. This one is located within a warehouse in Surrey, BC on top of the washroom roof.

Follow the manufacturer's installation recommendation for a GFCI breaker.

Demand Factor

We always give a demand factor of 100% for electric water heaters in our electrical load calculation. In an apartment building, these loads can add up quickly!

Bare Element Water Heaters

Bare element water heaters were a bit tricky to figure out. According to the CEC Section rule 62-410, the system:

  • Must be supplied from a grounded system.
  • Always use a separate circuit, a dedicated branch for the water tank.
  • The circuit breaker must be GFCI, Class A Type.
  • The heater can not be located with 1.5m of the point of utilization of the hot water.

What is a bare element water heater?

The typical storage-tank water heaters you see in residential and commercial buildings are not considered a bare element water heater, even though the element is in contact with the water.

After much research, we found that it is up to the manufacturer to clearly mark on their product if their unit is a "BARE ELEMENT WATER HEATER" (CSA C22.2 N. 64). If it isn't labelled on the nameplate, then it's not a bare element water heater!

Engineering Explanation

Ungrounded systems were used up to the 1950's and are very rare to come by these days. There are a few industrial installations that use ungrounded systems but most commercial and light-industrial complexes are now fully grounded and safer.

Water and electricity go dangerously well together and this is why the other rules are needed for bare element water heaters.

The heating element should be on a separate branch so that it can easily be disconnected without affecting any lighting or adjacent receptacles.

A GFCI, Class A breaker is required on a circuit feeding an electric water heater. Since the water usually enter near the top, if a leak were to happen, the electrical connectors can get flooded, posing an electrocution hazard.

A GFCI will detect the imbalance of the current leaving and returning on the circuit. Under this condition, it will automatically disconnect. This $100 investment in safety could potentially saving someone's life, your life.

Engineering Recommendation

Electrical consultants will recommend that flooded electric water heaters to be taken out of service and replaced. The wet insulation could potentially conduct electricity and could also result in inaccurate tank temperatures from the thermostat. Corroded wires also pose an arcing and fire hazard.

Connecting electric water heaters to the main panel is straight-forward according to the Canadian Electrical Code. The primary guidelines are to increase safety in the places where we work and live.